Constant-force spring

An ideal constant-force spring is a spring for which the force it exerts over its range of motion is a constant, that is, it does not obey Hooke's law. In reality, 'constant-force springs' do not provide a truly constant force and are constructed from materials which do obey Hooke's law.Generally constant-force springs are constructed as a rolled ribbon of spring steel such that the spring is in a rolled up form when relaxed. An ideal constant-force spring is a spring for which the force it exerts over its range of motion is a constant, that is, it does not obey Hooke's law. In reality, 'constant-force springs' do not provide a truly constant force and are constructed from materials which do obey Hooke's law.Generally constant-force springs are constructed as a rolled ribbon of spring steel such that the spring is in a rolled up form when relaxed.